Mystery of how the octopus never ties itself in knots solved: Tentacles are coated with repellent that stop suckers sticking together
- An octopus’ brain doesn’t know where each of its arms are at any one time
- But, despite the potential confusion, the creature doesn’t get tangled up
- Israeli scientists found this is because its suckers can't stick to themselves
- They temporarily shut down if they sense chemicals on an octopus' skin
- Researchers said amputated arms still grab after they’ve been removed
- But they fail to attach to other arms as long as they have skin on them
- Once the skin is removed, the arms grab, move and stick like normal
Scientists have worked out how an octopus avoids tying itself in knots.
As if having eight long and bendy arms to control isn’t tricky enough, the octopus’ brain doesn’t know exactly where they are at any one time. Yet, despite the potential confusion, the creature doesn’t get all tangled up.
This, say Israeli scientists, is because its arms will stick to just about anything - other than themselves.
An octopus' brain doesn't know exactly its arms are at any one time. Yet, despite the potential confusion, the creature doesn't get all tangled up. This, say Israeli scientists, is because its arms will stick to just about anything - other than themselves. Stock image pictured
INTELLIGENT OCTOPUSES ARE 'HONORARY VERTEBRATES'
are believed to be highly intelligent, more so than any other kind of
invertebrates; but their learning capability is still much debated among
creatures have been known to break out of aquariums and into others in
search of food, and they have even boarded fishing boats and opened
holds to eat crabs stored inside.
are the only invertebrate which has been shown to use tools, with some
species retrieving discarded coconut shells
and reassembling them to use as shelter.
tests they can be readily trained to distinguish
between different shapes and patterns.
It is thought the suckers that stud its arms temporarily shut down on sensing a chemical made by its skin.
The Hebrew University of Jerusalem researchers said: ‘We were entirely surprised by the brilliant and simple solution of the octopus to this potentially very complicated problem.’
The team from the university’s Octopus Research Group began by capitalising on the ability of the octopus’s arm to stay alive long after amputation.
Despite being able to move, grab and suck, amputated arms failed to attach to other arms – as long as they had skin on them.
If they had been skinned, they happily grabbed hold of them.
A close-up image of an octopus' suckers. They temporarily shut down if they sense a chemical on the octopus' skin. During tests the researchers said amputated arms still moved and grabbed after they'd been removed, but they failed to attach to other arms as long as they had skin on them
And when presented with skin in a plastic dish, they stuck to the dish but not to the skin.
Further experiments pointed to a substance made by the skin stopping the suckers from sucking.
Finally, the researchers showed that living octopuses can override the anti-knotting mechanism.
The journal Current Biology reports that this could be useful if the cannibalistic creatures spy a piece of octopus flesh they’d like to eat
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